Various types of holders have in the past been employed to support wet (e.g., recently printed or coated) two-piece can shells during transport from place to place, such as through curing or drying ovens and the like. Typically, the shells were simply inserted over pins projecting outwardly from a conveyor; while very simple and convenient to load and unload, such systems provided little security of support, and offered no opportunity to rotate the shells on the holders, and little by way of precise position control.
The so-called "spider" holder of, for example, U.S. Pats. Nos. 3,157,406, 3,298,700 and 3,365,158, and the "brush" holder typified by U.S. Pat. No. 3,334,904 improved upon the noted deficiencies of the simple pin-type mounting. However, so far as is known, no presently-available holder for hollow articles offers adequate levels of support and position control, while also enabling efficient rotation of the mounted article. These features tend to be critical in connection with current ultraviolet light curing operations, wherein the relationships between the coated surface and the incident UV beam have a significant effect upon the results achieved. Finally, in present-day high-speed can printing and decorating operations, it is imperative that the holder be capable of accepting and releasing the shells rapidly and without damage to either the workpiece or the transporting equipment, and this must be done not only while affording the above-noted features, but also even in the event of misalignment of skewing of the shells as they are presented to the holders.
Accordingly, it is an object of the present invention to provide a novel holder on which a hollow article may be firmly supported in a relatively precise position, and readily rotated thereby.
IT IS ALSO AN OBJECT OF THE INVENTION TO PROVIDE SUCH A HOLDER UPON AND FROM WHICH THE ARTICLE MAY BE RAPIDLY AND FACILELY LOADED AND WITHDRAWN, WITHOUT DAMAGE TO THE ARITCLE OR TO THE HOLDER, AND NOTWITHSTANDING THAT THE ARTICLE BE PRESENTED TO THE HOLDER IN AN ACUTE ANGULAR RELATIONSHIP TO ITS AXIS.
A more specific object is to provide a novel holder having the foregoing features and advantages, which holder is simple and convenient to use, and is especially adapted for the efficient transport of can shells through a UV-curing system.